title: Cysteine proteinase changes during macrocyst formation in Dictyostelium mucoroides.
abstract: Cysteine proteinases were detected in vegetative myxamoebae of Dictyostelium mucoroides DM7 using chromogenic substrates and by electrophoretic analysis (gelatin-SDS-PAGE) which revealed three enzymes, dmCP30, dmCP35 and dmCP46 (a minor form). During the initial stages of macrocyst formation the cysteine proteinaes were secreted and disappeared almost completely from the cells. High extracellular levels of activity towards N-benzoyl-L-prolyl-L-phenylalanyl-L-arginine 4-nitroanilide and of dmCP30 persisted throughout macrocyst development. Three new intracellular proteinases, dmCP31, dmCP36 and dmCP40, were produced as macrocysts formed but their activity was only detected by gelatin-SDS-PAGE. Their appearance was specific to the developmental pathway leading to macrocyst formation. This is the first direct evidence for the accumulation of cysteine proteinases during a developmental process in a cellular slime mould.
authors.affiliation: Department of Biological and Molecular Sciences, School of Natural Sciences, University of Stirling, U.K.
authors.forename: M J
authors.initials: MJ
authors.lastname: North
authors.forename: D A
authors.initials: DA
authors.lastname: Cotter
authors.forename: K J
authors.initials: KJ
authors.lastname: Franek
mesh_terms: D000595:Amino Acid Sequence; D003546:Cysteine Endopeptidases / Q000378:metabolism*; D004023:Dictyostelium / Q000201:enzymology* / Q000254:growth & development; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000378:metabolism
chemical_list: D009842:Oligopeptides; D003546:Cysteine Endopeptidases